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Abstract:

A method (200) for determining the noise floor in a receiver, comprising
sorting (210) received estimated values of the noise floor by time bins
in a time cycle, determining and storing the average value of the
received values in each time bin for a previous time cycle and
determining (220) a scale factor for each time bin in the current time
cycle, by dividing the average value of each time bin in the previous
time cycle by the smallest average value of the time bins in the previous
time cycle. The division for time bin k in the previous time cycle is
used as scale factor for time bin k in the current time cycle, and the
method further comprises determining (225) applying the scale factor of
the current time bin to the currently received estimated value of the
noise floor power level.

Claims:

1-16. (canceled)

17. A method for determining the noise floor power level in a radio
receiver, the method comprising: receiving estimated values of the noise
floor power level; sorting the received estimated values by time bins,
the time bins being N predetermined portions of a predetermined time
cycle; determining the average value of the received values in each time
bin for a previous time cycle; determining a scale factor for each time
bin k in the current time cycle by dividing an average value of each time
bin k in the previous time cycle by a smallest average value of the time
bins in the previous time cycle; determining a compensated noise floor
power level for each time bin in the current time cycle by applying the
scale factor of the current time bin to the currently received estimated
value of the noise floor power level.

18. The method of claim 17 further comprising: storing the received
estimated values of the noise power floor; determining the average values
of the time bins in the previous time cycle based on the stored received
estimated values of the noise power floor.

19. The method of claim 17 further comprising: storing the average value
of the received values in each time bin for the previous time cycle;
determining the smallest average value of the time bins in the previous
time cycle after all average values of the time bins in the previous time
cycle have been stored.

20. The method of claim 17, further comprising determining and storing an
average value of the received values in each time bin for the current
time cycle for use in determining a scale factor for a future time cycle.

21. The method of claim 20, wherein the future time cycle is the
immediately next time cycle.

22. The method of claims 17, wherein the applying the scale factor of the
current time bin to the currently received estimated value of the noise
floor power level comprises dividing the currently received estimated
value of the noise floor power level by the scale factor of the current
time bin.

23. The method of claim 17, wherein the previous time cycle used in
determining the scale factors for the current time cycle is the time
cycle immediately preceding the current time cycle.

24. The method of claim 17, wherein the predetermined time cycle is a 24
hour period and N equals 24.

25. A device for determining the noise floor power level in a radio
receiver, the device comprising: one or processing circuits, the
processing circuits configured to operate as: an averaging circuit
configured to: receive estimated values of the noise floor power level;
sort the received estimated values by time bins, the time bins being N
predetermined portions of a predetermined time cycle, determine an
average value of the received values in each time bin for a previous time
cycle; a scale factor circuit configured to: receive, from the averaging
circuit, the average values of the bins for the previous time cycle
determine a scale factor for each time bin k in the current time cycle by
dividing an average value of each time bin k in a previous time cycle by
a smallest average value of the time bins in the previous time cycle, a
determining circuit configured to determine a compensated noise floor
power level for each time bin in the current time cycle by applying the
scale factor of the current time bin to the currently received estimated
value of the noise floor power level.

26. The device of claim 25, wherein the averaging circuit is configured
to: store the received estimated values of the noise power floor;
determine the average values of the time bins in the previous time cycle
from the stored received estimated values of the noise power floor.

27. The device of claim 25: further comprising storage configured to
store the determined average values of the time bins in the previous time
cycle wherein the device is configured to find the smallest average value
of the time bins in the previous time cycle after all of the average
values of the time bins in the previous time cycle have been stored.

28. The device of claim 25, wherein the device is configured to determine
and store the average value of the received values in each time bin for
the current time cycle for use in determining a scale factor for a future
time cycle.

29. The device of claim 28, in which the future time cycle is the
immediately next time cycle.

30. The device of claim 25, wherein the determining circuit is configured
to apply the scale factor of the current time bin to the currently
received estimated value of the noise floor power level by dividing the
currently received estimated value of the noise floor power level by the
scale factor of the current time bin.

31. The device of claim 25, wherein the scale factor circuit is
configured to use the time cycle immediately preceding the current time
cycle as the previous time cycle in determining the scale factor.

32. The device of claim 25, wherein the averaging circuit is configured
to use a 24 hour period as the predetermined time cycle, with N being set
to equal 24.

Description:

TECHNICAL FIELD

[0001] The present invention discloses a method and a device for improved
estimation of the noise floor power level in a radio receiver.

BACKGROUND

[0002] An accurate estimate of the momentary air interface load of the
uplink in a cellular system such as a WCDMA system is necessary in order
to enable accurate scheduling of users of the uplink, exemplified by the
enhanced uplink, EUL, in WCDMA and for the accurate admission of new
users of the WCDMA uplink. Inaccuracies in the estimation of the
momentary air interface load of the WCDMA uplink will result in a
reduction of the throughput of the WCDMA EUL uplink.

[0003] The air interface load is expressed as a so called noise rise, i.e.
the total amount of (relevant) interference power, divided by the thermal
noise of the WCDMA uplink receiver. From this, it follows that in order
to obtain an accurate estimation of the air interface load, it is also
necessary to obtain an accurate estimation of the thermal "noise floor"
in the receiver--due, for example, to the fact that variations in
electronics components result in thermal noise floor variations of 1-3 dB
between different uplink receivers, i.e. NodeBs with the continued use of
a WCDMA system as an example, and also due to the fact that factory
calibration would be costly as well as being uncertain due to highly
varying installation procedures and corresponding variations in cabling
losses.

[0004] Estimation of the thermal noise floor in the receiver in a WCDMA
NodeB is a difficult problem, one of the sources of the difficulty being
that it is not possible to distinguish between interference from
neighboring cells and the receiver's internal noise, i.e. the receiver's
thermal noise.

[0005] Interference from neighboring cells will thus often cause an
estimation of the receiver's internal noise floor to be too high. In
addition, the amount of interference from neighboring cells varies over
time, a fact that sometimes allows for accurate noise floor estimation
and sometimes not. A remedy for time-varying interference from
neighbouring cells would of course be to extend the period of time over
which the internal noise floor is estimated. However, this has two
distinct drawbacks: first of all, the bandwidth of the noise floor
estimator will be reduced, and secondly, the amount of data needed for
the estimations is increased.

[0006] In addition, the "always connected" ambition of the cellular
industry, together with the ambition to have a large number of users,
e.g. smart phones and machines, which simultaneously use the uplink will
make the problem of "seeing" the internal noise floor in a receiver in a
NodeB much worse in the future, due to the fact that "always connected"
devices will transmit with low intensity, and the large amounts of such
users will greatly reduce the variation of the uplink load, simply due to
"the law of large numbers", thus making the interference level appear as
slightly varying around a mean value that varies slowly.

[0007] There exist methods for estimating the internal noise floor in a
receiver, but these known methods exhibit a number of disadvantages. Some
known methods include so called bias estimation, and some don't. Known
methods without bias estimation exhibits such disadvantages as providing
estimates that are biased towards positive values and of providing
estimates that vary substantially over time. Known methods with bias
estimation exhibit disadvantages that include, for example, an inability
to provide a sufficient amount of bias reduction, i.e. they are not
accurate enough, in addition to which they do not provide bias
estimations with a sufficiently high degree of resolution, e.g. by the
hour per day, as well as being unable to provide bias estimations that
perform differently for different weekdays, which would be necessary due
to the fact that the uplink traffic intensity varies between, for
example, weekdays and weekends. In addition, such known methods for
estimating the internal noise floor in a receiver often rely on auxiliary
measurements, which requires the development of auxiliary interfaces and
signal transfer protocols.

[0008] In addition, as mentioned previously, known methods for estimating
a receiver's internal noise floor are not able to cope with the "always
connected" ambition of the cellular industry, in connection with the
ambition to have large numbers of users, e.g. smart phones and machines,
which simultaneously use the uplink.

SUMMARY

[0009] As has emerged from the text above, a problem within cellular
technology such as, for example, WCDMA, is to properly determine the
internal noise floor, here also referred to as the noise floor power
level, in a receiver. This problem is addressed by the invention in that
it discloses a method for determining the noise floor power level in a
radio receiver, which comprises receiving estimated values of the noise
floor power level and sorting the received estimated values by time bins.

[0010] The time bins are N predetermined portions of a predetermined time
cycle, and the method also comprises determining the average value of the
received values in each time bin for a previous time cycle.

[0011] In addition, the method also comprises determining a scale factor
for each time bin k in the current time cycle by means of dividing the
average value of each time bin k in the previous time cycle by the
smallest average value of the time bins in the previous time cycle.

[0012] The result of the division for time bin k in the previous time
cycle is used as scale factor for time bin k in the current time cycle,
and the method further comprises determining a compensated noise floor
power level for each time bin in the current time cycle by means of
applying the scale factor of the current time bin to the currently
received estimated value of the noise floor power level.

[0013] By means of the invention as will be shown in the following
detailed text with reference to the appended drawings, an improved
performance is obtained in determining the noise floor power level in a
radio receiver in a cellular system such as, for example, WCDMA.

[0014] In some embodiments of the method, the received estimated values of
the noise power floor are stored, and the average values of the time bins
in the previous time cycle are determined from the stored received
estimated values of the noise power floor.

[0015] In some embodiments of the method, the average value of the
received values in each time bin for the previous time cycle are stored
and the smallest average value of the time bins in the previous time
cycle is determined when all of the average values of the time bins in
the previous time cycle have been stored.

[0016] In some embodiments, the method also comprises determining and
storing the average value of the received values in each time bin for the
current time cycle for use in determining a scale factor for a coming
time cycle. In some such embodiments of the method, the coming time cycle
is the next time cycle.

[0017] In some embodiments of the method, the step of applying the scale
factor of the current time bin to the currently received estimated value
of the noise floor power level comprises dividing the currently received
estimated value of the noise floor power level by the scale factor of the
current time bin.

[0018] In some embodiments of the method, the previous time cycle used in
determining the scale factor is the time cycle immediately preceding the
current time cycle.

[0019] In some embodiments of the method, the predetermined time cycle is
a 24 hour period and K equals 24.

[0020] The invention also discloses a device for determining the noise
floor power level in a radio receiver. The device comprises an averaging
component which is arranged to receive estimated values of the noise
floor power level and to sort the received estimated values by time bins,
where the time bins are N predetermined portions of a predetermined time
cycle.

[0021] The averaging component is also arranged to determine the average
value of the received values in each time bin for a previous time cycle,
and the device also comprises a scale factor component arranged to
receive from the averaging component the average values of the bins for
the previous time cycle. The scale factor component is arranged to
determine a scale factor for each time bin k in the current time cycle by
dividing the average value of each time bin k in the previous time cycle
by the smallest average value of the time bins in the previous time
cycle, and to use the result of the division for time bin k in the
previous time cycle as scale factor for time bin k in the current time
cycle.

[0022] The device further comprises a determining component which is
arranged to determine a compensated noise floor power level for each time
bin in the current time cycle by means of applying the scale factor of
the current time bin to the currently received estimated value of the
noise floor power level.

[0023] In some embodiments, the averaging component is arranged to store
the received estimated values of the noise power floor, and to determine
the average values of the time bins in the previous time cycle from the
stored received estimated values of the noise power floor.

[0024] In some embodiments, the device is also arranged to store the
determined average values of the time bins in the previous time cycle,
and to find the smallest average value of the time bins in the previous
time cycle when all of the average values of the time bins in the
previous time cycle have been stored.

[0025] In some embodiments, the device is also arranged to determine and
store the average value of the received values in each time bin for the
current time cycle for use in determining a scale factor for a coming
time cycle. In some such embodiments, the coming time cycle is the next
time cycle.

[0026] In some embodiments of the device, the determining component is
arranged to apply the scale factor of the current time bin to the
currently received estimated value of the noise floor power level by
dividing the currently received estimated value of the noise floor power
level by the scale factor of the current time bin.

[0027] In some embodiments, the previous time cycle which is used by the
scale factor component in determining the scale factor is the time cycle
immediately preceding the current time cycle.

[0028] In some embodiments of the device, the predetermined time cycle
used by the averaging component is a 24 hour period, with K being set to
equal 24.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The invention will be described in more detail in the following,
with reference to the appended drawings, in which

[0030]FIG. 1 shows an example of a prior art system for determining the
noise power floor level in a radio receiver, and

[0033] FIGS. 4-7 show examples of results achieved by means of the
invention.

DETAILED DESCRIPTION

[0034] Embodiments of the present invention will be described more fully
hereinafter with reference to the accompanying drawings, in which
embodiments of the invention are shown. The invention may, however, be
embodied in many different forms and should not be construed as being
limited to the embodiments set forth herein. Like numbers in the drawings
refer to like elements throughout.

[0035] The terminology used herein is for the purpose of describing
particular embodiments only, and is not intended to limit the invention.

[0036] First, a few terms used in this text will be defined: as stated, an
object of the invention is to enable accurate determination of the noise
floor power level in a radio receiver, i.e. the level of internal noise
in the receiver caused by random fluctuations in electronic circuitry,
which in turn is needed in order to enable an accurate determination of
the receiver's so called RoT, Rise over Thermal, i.e. the current noise
power level in the receiver as referred to the receiver's noise floor
power level. The RoT value at time t, i.e. RoT(t), is defined as:

RoT ( t ) = RTWP ( t ) N ( t ) ( 1 )
##EQU00001##

[0037] In (1) above, N(t) is the thermal noise level at an antenna
connector of the radio receiver and RTWP(t) is the total wideband power
at the antenna connector which is used in the definition of N(t). RTWP(t)
is given by the following expression:

[0038] In (2) above, IN(t) denotes the power received in interference
from neighbouring cells (N) in the cellular system, for example a
WCDMA system. A major difficulty when estimating the RoT in a radio
receiver in a cellular system is to separate the receiver's noise floor
power level from the interference which is received from neighboring
cells.

[0039] As will be shown in the following, the invention discloses a method
and a corresponding device for determining the noise floor power level of
a radio receiver in a cellular system without undue influence from
interference from neighbouring cells.

[0040] A simplified block diagram of a prior art system 100 for
determining a radio receiver's RoT is shown in FIG. 1, and will be
described here briefly: a Kalman filter 105 receives values of RTWP over
time, shown as XRTWP(t), filters these values and delivers them to a
component 110 for determining the RoT. The component 110 also receives
estimates of the noise floor power level from an estimator 115, which can
be an estimator which works on either, for example, a sliding window
principle or a recursive estimator. The receiver's RoT can then be
determined in the component 110 by means of comparing the filtered values
of RTWP with the estimated values of the noise floor power level. In the
example of an estimator 115 shown in FIG. 1, the Kalman filter 105
delivers to the estimator 115 values fRTWP(x, t) of the probability
density function associated with an estimate x of the RTWP at a point in
time t. The probability density function is Gaussian and is therefore
fully defined by the covariance matrix and the mean, both quantities
being estimated on line in the Kalman filter. In addition, the estimator
115 also uses an initial (i.e. t=0) value of f0RTWP(X).

[0041] Prior art systems such as the one in FIG. 1 suffer from problems
such as not being able to sufficiently isolate the noise caused by
interference from the "noise floor power level" of the radio receiver.

[0042] An aim of the invention is thus to improve upon a prior art system
such as the one in FIG. 1 by means of determining a scale factor which is
applied to estimated values of the noise floor power level, such as those
which are estimated by, for example, an estimator such as the estimator
115 of FIG. 1. It is however stressed that the invention can be applied
to values which are estimated either by means of sliding window methods
or recursive methods, or, in principle, by any other method.

[0043] The scale factor q(t) is determined as follows, which will be
described with reference to the flow chart 200 of FIG. 2: estimated
values of the noise floor power level are received, step 205, from an
estimator such as the one 115 in FIG. 1. The received estimated values
are sorted by time bins, step 210, where the time bins are N
predetermined portions of a predetermined time cycle. As an example, the
predetermined time cycle can be a 24 hour period, where each time bin is
one of the 24 hours, and N then becomes 24. Alternatively, the time cycle
can be a week, i.e. 7*24 hours, in which case the time bins are suitably
still the hours of the time cycle. In some embodiments, the received
estimated values of the noise floor power level are stored, step 207.

[0044] The average value x of the received values in each time bin for at
least one previous time cycle are determined, step 215. The term
"previous cycle" is here used in the sense that it refers to a time cycle
which has preceded the current one. The current time cycle is referred to
in FIG. 2 as time cycle L, and the previous time cycle is then referred
to as time cycle L-M, where M is a positive integer ≧1. In some
embodiments, the averages are stored, as shown in step 217, in order to
find the smallest average value of the time bins in the previous time
cycle.

[0045] A scale factor is determined, step 220, for each time bin k in the
current time cycle, where k is in the integer interval [1,N] and where
the current time cycle is referred to as time cycle L. This is done by
means of dividing the average value of each time bin k in the previous
time cycle, i.e. time cycle L-M, by the smallest average value of the
time bins in the previous time cycle. The result of this division for
time bin k in the previous time cycle L-M is used as scale factor for
time bin k in the current time cycle L. Thus, using the example of two
immediately adjacent time cycles which are 24 hour periods, and using the
hours of the time cycles as the time bins, with the second 24 hour period
as the current time cycle, the scale factor for the time bins of the
current time cycle, i.e. hours 25-48, is determined as follows: assume
that it is hour 5 that has the smallest average value of hours 1-24. The
scale factor for each hour 25-48 is then determined by dividing the
average value for each hour in the previous time cycle, i.e. the average
values for hours 1-24, by the smallest average value of the hours 1-24,
in this example the average value of hour 5.

[0046] In this manner, 24 scale factors are obtained, which can be
numbered as 1-24 by their hours. Scale factors 1-24 obtained in this way
are then used for hours 1-24 of the current time cycle: in other words,
the scale factor obtained by dividing the average value of hour 1 by the
average value of hour 5 in the previous time cycle is used for hour 1 in
the current time cycle, i.e. hour 25, and the scale factor obtained by
dividing the average value of hour 2 by the average value of hour 5 in
the previous time cycle is used for hour 2 in the current time cycle,
i.e. hour 26, etc. In this manner, scale factors are obtained for all of
the hours (time bins) of the current time cycle.

[0047] Since scale factors have now been obtained for each of the time
bins in the current time cycle, compensated noise floor power levels for
the current time cycle can be determined, step 225, which is done by
applying the scale factor of the current time bin to the estimated values
of the noise floor power level which are received. As an example, for an
estimated value received at time 17:12 of the current time cycle
(sticking to the example of 24 hour periods as time cycles), the scale
factor of time bin 18 of the current time cycle is used.

[0048] The scale factor can be applied to the received estimated values in
a number of different ways, depending on how the scale factor is
determined and how the compensated noise floor power level is to be used,
but in one example, the currently received estimated value of the noise
floor power level is divided by the scale factor of the current time bin.
In the example used above, this would mean dividing the estimated value
received at 17:12 of the current time bin by the scale factor of time bin
18 of the current time cycle.

[0049] Some embodiments of the method also comprise determining and
storing the average value of the received values in each time bin for the
current time cycle for use in determining a scale factor for a coming
time cycle.

[0050] A system 300 which uses the invention is shown in FIG. 3, where
reference numbers from FIG. 1 have been retained for corresponding
components. The system 300 will be described in the following as a system
in which scale factors are determined on a continuous basis, although it
should be understood that in some embodiments, the scale factors need
only be determined for the current time cycle, which is then done by
means of estimated values of the noise floor power level from one
previous time cycle, suitably the time cycle immediately preceding the
current one. In addition, the system 300 will be described as storing
received estimated values of the noise floor power level, in order to
determine the averages, as well as storing the determined averages in
order to find the smallest average. Again, this is merely one example of
a suitable embodiment, both the averages and the smallest average can,
for example, be determined "on the fly" instead.

[0051] The system 300 comprises the components of the system 100 of FIG.
1, and as shown by means of dashed lines, the system 300 also comprises a
device of the invention, indicated as 301 in FIG. 3. As shown in FIG. 3,
the system 300 by means of the invention 301 determines a scale factor q
for each time bin k in a time cycle, and the proper q(t) is applied to
the estimated values xthermal(t)of the noise power floor from the
estimator 115. The proper q(t) is chosen by finding the correct time bin
of the time t, as explained above in the example where the time t was
17:12 and the correct time bin was then time bin number 18.

[0052] In the example of FIG. 3, the scale factor q(t) is shown as being
applied to xthermal(t) by means of division, i.e.
xthermal(t)/q(t) in a component 325 for division. However, it should
naturally be understood that the scale factor q(t) can also be determined
such that it instead should be multiplied by xthermal(t), i.e. q(t)*
xthermal(t). The scale factor is then determined as the inverse of
the scale factor xthermal(t)

[0053] The invention is shown in FIG. 3 as comprising two main components
apart from the component 325 for division: one component 315 for
averaging and storing, and one component 320 for determining the scale
factor for bin k using the input from the component 315. The function of
the component for averaging and storing 315 corresponds to steps 205-217
of FIG. 2, and the function of the component 320 for determining the
scale factor corresponds to step 220 of FIG. 2. It should be pointed out
that the division of the tasks carried out by of the invention in the
components 315 and 320 is merely one of many ways in which the invention
can be implemented.

[0054] The function of the components 315 and 320 and will now be
explained more closely.

[0055] The averaging and storing component 315 uses a running time cycle,
Ix, typically of a length of one day or one week, which thus
corresponds to the time cycles mentioned previously. As also explained
previously, this time cycle is then divided into time bins,
iix=[tilow, tihigh], i=1 . . . N, which as
mentioned typically represent one hour each.

[0056] The averaging and storing component 315 also uses an internal bias
estimation time, thbias which, for example, may be initialized
when the load estimation functionality of the NodeB is started, since the
load estimation involves determining the RoT. The internal bias
estimation time tjbias is reset by a modulo operation when the
end of a time cycle has been reached, i.e. as:

i tjbias=mod(tj-1bias+Δt,tNhigh-t.su-
b.1low)

where Δt is the time between noise power floor updates in the
estimator 115. An example of a typical such time Δt is 20 minutes.

[0057] The aim of the function of the averaging and storing component 315
is to estimate the average noise power floor in each time bin, in order
to capture the estimated noise floor variations over the time cycle, e.g.
the day, week, etc, and to then, in one example of an embodiment, store
this value for each time bin.

[0058] Updates are performed in the averaging and storing component 315 as
updates of the estimated noise floor power level are received from the
estimator 115, and are performed as follows:

where a is an adaptation time constant, suitably selected to be
significantly larger than Ix, and where the following is also
assumed for the sake of simplicity: tj-1bias ε
iix=[tilow, tihigh]

[0059] In order to avoid update transients, the noise power floor
variables, corresponding to the previous complete update of all bins are
stored and used for bias compensation.

[0060] Note that the above description of the function of the averaging
and storing component 315 assumes power levels expressed in the linear
domain, i.e. as [W]. In case of very large daily variations, it may
instead be beneficial to express and update the powers in the logarithmic
domain instead, i.e. as [dBm].

[0061] The component 320 for determining the scale factor corresponds to
step 220 of FIG. 2, and functions in the following manner:

[0062] The component 320 determines a scale factor to be applied to the
"raw" estimate of the noise power floor as received from an estimator
such as the one 115 in FIGS. 1 and 2. A principle used here is that the
minimum estimate noise floor value over the cycle Ix, i.e.

ximinthermal=min(xithermal,i=1 . . . N)

is first determined from the (complete last update) of the noise power
floor variables of all bins, i.e. per day, week or in general, the time
cycle which is divided into the N bins. Then it is checked which time
cycle Iix=[tilow, tihigh], i=1 . . . N that
the current bias estimation belongs to, and a scale factor k(t) is
computed as:

[0063] This scale factor k(t) expresses the factor by which the estimated
noise power floor is above the minimum value, as taken over the cycle
Ix. This means that a division of the estimated noise power floor
received from the estimator 115 by this scale factor will, at least
ideally, compensate for the rise of the noise power floor due to daily
variations of the traffic. The compensated value
xcompensatedthermal(t) of the estimate xthermal(t) is
obtained as:

as is shown at block 325 in FIG. 3. Note that the value of the scale
factor is held constant at least until the next update of the noise power
floor level from the estimator 115. This is due to the fact that the
components 315 and 320 should operate at the same rate.

[0064] In order to assess the performance of the invention, a simulation
over 30 days has been performed. The data was a mix of speech and data
traffic, which was organized so as to generate traffic variations over
the day. The true thermal noise power floor was -106.5 dB, and a
recursive noise power floor estimation method was applied with a time
constant of 1 hour. The adaptation rate of the bias estimation algorithm
was 5 days.

[0065] A number of performance parameters were then calculated with and
without the invention, i.e. with and without the bias estimation and bias
compensation of FIG. 2. The values are based on the last 15 days of the
simulation, after initial convergence of the bias estimator. The values
obtained are shown in the table in FIG. 4.

[0066] Results obtained by means of the invention are also shown in FIGS.
5-7: FIG. 5 shows the data traffic variation, expressed as RTWP, over
time, together with the variation of the noise floor, with and without
application of the invention, and FIG. 6 shows the variation of the
estimated noise power floor without and with the invention, the latter
being indicated as "compensated noise floor". Finally, FIG. 7 shows the
estimated noise rise using the invention.

[0067] Embodiments of the invention are described with reference to the
drawings, such as block diagrams and/or flowcharts. It is understood that
several blocks of the block diagrams and/or flowchart illustrations, and
combinations of blocks in the block diagrams and/or flowchart
illustrations, can be implemented by computer program instructions. Such
computer program instructions may be provided to a processor of a general
purpose computer, a special purpose computer and/or other programmable
data processing apparatus to produce a machine, such that the
instructions, which execute via the processor of the computer and/or
other programmable data processing apparatus, create means for
implementing the functions/acts specified in the block diagrams and/or
flowchart block or blocks.

[0068] These computer program instructions may also be stored in a
computer-readable memory that can direct a computer or other programmable
data processing apparatus to function in a particular manner, such that
the instructions stored in the computer-readable memory produce an
article of manufacture including instructions which implement the
function/act specified in the block diagrams and/or flowchart block or
blocks.

[0069] The computer program instructions may also be loaded onto a
computer or other programmable data processing apparatus to cause a
series of operational steps to be performed on the computer or other
programmable apparatus to produce a computer-implemented process such
that the instructions which execute on the computer or other programmable
apparatus provide steps for implementing the functions/acts specified in
the block diagrams and/or flowchart block or blocks.

[0070] In some implementations, the functions or steps noted in the blocks
may occur out of the order noted in the operational illustrations. For
example, two blocks shown in succession may in fact be executed
substantially concurrently or the blocks may sometimes be executed in the
reverse order, depending upon the functionality/acts involved.

[0071] In the drawings and specification, there have been disclosed
exemplary embodiments of the invention. However, many variations and
modifications can be made to these embodiments without substantially
departing from the principles of the present invention. Accordingly,
although specific terms are employed, they are used in a generic and
descriptive sense only and not for purposes of limitation.

[0072] The invention is not limited to the examples of embodiments
described above and shown in the drawings, but may be freely varied
within the scope of the appended claims.

Patent applications by Torbjorn Wigren, Uppsala SE

Patent applications by Torbjörn Wigren, Uppsala SE

Patent applications by TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)

Patent applications in class Measuring or testing of receiver

Patent applications in all subclasses Measuring or testing of receiver